Both methods rely on engineering T cells—the hungry predator cells of the immune system—so they attack leukemic cells.
The British infants, ages 11 and 16 months, each had leukemia and had undergone previous treatments that failed, according to a description of their cases published Wednesday in Science Translational Medicine. Waseem Qasim, a physician and gene-therapy expert who led the tests, reported that both children remain in remission.
Although the cases drew wide media attention in Britain, some researchers said that because the London team also gave the children standard chemotherapy, they failed to show the cell treatment actually cured the kids. “There is a hint of efficacy but no proof,” says Stephan Grupp, director of cancer immunotherapy at the Children’s Hospital of Philadelphia, who collaborates with Novartis. “It would be great if it works, but that just hasn’t been shown yet.”